DOCUMENT:Q245192 10-AUG-2001 [winnt] TITLE :Blank Logon Dialog Box Appears After You Change Drive Letter. PRODUCT :Microsoft Windows NT PROD/VER:winnt:4.0 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 4.0 ------------------------------------------------------------------------------- SYMPTOMS ======== When you restart a computer running Microsoft Windows NT Server 4.0, and then press CTRL+ALT+Delete to log on to the computer, you may receive a blank dialog box. CAUSE ===== This behavior can occur if you install a new hard disk on your computer and change the drive letter of the hard disk, and the Winlogon.exe, Samsrv.dll, or Samlib.dll files are damaged, or the Security Accounts Manager (SAM) database is damaged. RESOLUTION ========== To resolve this issue, use an Emergency Repair Disk (ERD) to restore the damaged system files, and then restore the SAM and Security registry hives from the most recent tape backup. MORE INFORMATION ================ Though restoring the registry hives from the most recent tape backup is the preferred method, you can also restore the SAM and Security registry hives from the ERD. CAUTION: The ERD method restores the hives only to how they were when you created the ERD. All the user account and user group information is lost. Updating an ERD does not update the SAM and Security hives. For more information about updating the SAM and Security hives, please refer to the following article in the Microsoft Knowledge Base: Q126464 Repair Disk Utility Does Not Update SAM and Security Hives For more information about using an ERD, please refer to the following article in the Microsoft Knowledge Base: Q103280 Using an Emergency Repair Disk Created by Windows NT For more information about restoring the registry from a tape backup, please refer to the following Microsoft Knowledge Base article: Q101229 How to Restore Windows NT Over an Existing Installation Additional query words: domain missing ====================================================================== Keywords : Technology : kbWinNTsearch kbWinNT400search kbWinNTSsearch kbWinNTS400search kbWinNTS400 Version : winnt:4.0 Issue type : kbprb ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.